"A surprise for them instead of the one they intended for me," thought Royce. "I hope they won't try it again; it is hateful to shoot the poor wretches, but there's nothing else for it if they attack." Only the knowledge of the miseries these pests of the country had inflicted on scores of peaceable villages reconciled Royce to the part he felt himself called upon to play. He seized the occasion to impress upon his men the necessity for watchfulness while on duty. "Your falling asleep," he said to the two repentant sentries, "might have led to the capture of the fort, and the death or enslavement of all of us. Take care in future." During the day it occurred to him that the men would be all the better for active employment. At the same time, in view of the attempted surprise, it was advisable still further to strengthen their defences. Accordingly, he set them to dig a ditch a few feet inside the wall. The proper place for it was outside, of course; but to dig it there would expose them to danger. Moreover, the Tubus might fill it up or bridge it. If it were inside, on the other hand, it would form an unexpected obstacle should they scale the wall. There was not enough water to make a moat of it; but, dug to a depth of several feet, it would seriously embarrass the attackers, even though dry. The men at the north-east corner, when they had dug about six feet below the surface, came suddenly upon something hard, upon which the sharpened stones they used as spades made no impression. They reported the discovery to Royce, who went to the spot and jumped down so that he might examine the obstruction. It proved to be a course of brickwork. Taking the spade, Royce dug the earth away from its edge for several feet, wondering what purpose the bricks served. [Illustration: THE DISCOVERY IN THE DITCH] Perhaps, he thought, they were part of some building still more ancient than the fort itself. It would be interesting to excavate more thoroughly, and find out whether anything of value, in the shape of old weapons, coins, or pottery, lay beneath the foundations. But that must be a task for the future. At present the business in hand was the completion of the ditch. The bricks being almost level with the bottom of the part which had already been dug out, he decided that it was unnecessary to remove them, and he ordered the men to go on with their work in another direction. By dusk that evening the ditch was half finished. Royce, after eating his scanty supper, was sitting alone, tired out, wondering what had happened to Challis, whether he would succeed in getting help, how long it would be before he came back. All at once he heard a shout of alarm, followed by a cry of pain. Springing up, he rushed in the direction of the sounds. The whole garrison was in a ferment, and two of the men had reached the scene before him. "What is it?" he cried, thinking that perhaps some of the men had been quarrelling.